MONDAY, Jan. 13, 2014 (HealthDay News) -- Nearly 2.2 million Americans had selected health plans through the federal and state marketplaces as of late December, and nearly one in four was a young adult, the Obama administration disclosed Monday.
"The numbers show that there is a very strong national demand for affordable health care made possible by the Affordable Care Act," Health and Human Services (HHS) Secretary Kathleen Sebelius said during a news conference Monday afternoon.
"More than 6 million Americans have now either signed up for private health insurance plans or for Medicaid coverage through the marketplace," she said.
Twenty-four percent of people who chose a plan were in the key 18-to-34-year-old demographic.
Attracting enough young adults to the mix should keep health insurance rates more affordable, experts say. Young people tend to be healthier, helping to offset the risk of covering older, sicker adults.
"For the 18-34 age band, we would want at least 32 percent of the adult sign-ups [people ages 18 to 64] to be in that category," said David Axene, president and consulting actuary at Axene Health Partners, of Murrieta, Calif.
"Materially less than that leads to subsidy concerns," he added.
Sebelius highlighted a rosier statistic during Monday's news conference, noting that 30 percent of enrollees were under age 35. But that figure includes people 17 and younger who are not yet considered adults.
"It's hardest to enroll the younger people, and so they're not going to enroll until the deadlines get closer," said Gary Claxton, vice president and director of the Health Care Marketplace Project at the Henry J. Kaiser Family Foundation in Washington, D.C.
Open enrollment in the health marketplaces ends March 31.
"What matters obviously is what happens by the end of March," Claxton said.
Mike Hash, director of the HHS Office of Health Reform, told reporters Monday that "the trends so far are suggestive of an appropriate mix in the marketplace."
With 11 weeks to go before the enrollment period ends for insurance coverage in 2014, "we expect an increase in the proportion of young adults as we go forward," he said.
In all, 9 million people have selected coverage, Sebelius said. That includes private marketplace coverage, Medicaid and the 3 million young adults who have already gained coverage because the Affordable Care Act allows them to stay on their parents' health plans until age 26.
The report released Monday covered enrollment through Dec. 28, 2013. It's the federal government's third report since the marketplaces opened on Oct. 1, 2013.
Enrollment surged during December, with 1.8 million people selecting a health plan -- a five-fold increase over the number of consumers who signed up in October and November combined.
Seventy-nine percent of people signing up for marketplace insurance plans have received financial assistance in the form of tax credits.
By gender, a greater percentage of women than men (54 percent versus 46 percent) have enrolled for "Obamacare" through the online marketplaces.
The federal registration portal -- HealthCare.gov -- received more than 53 million website visits through the Oct. 1-Dec. 28 period. State and federal call centers have received more than 11 million phone calls, the report said. HealthCare.gov was initially plagued by computer glitches that made the site almost unusable for the first several weeks of operation.
It's still not known how many people who signed up for coverage have paid their premiums -- the final step for ensuring coverage.
Julie Bataille, a spokeswoman for Centers for Medicare & Medicaid Services' Office of Communications, said the federal government is "ramping up outreach activities" to make sure people know they can enroll in marketplace coverage and pay those premiums.
The Congressional Budget Office had estimated last year that 7 million people would sign up for Obamacare through the online exchanges by 2014.
The federal exchange, HealthCare.gov, is the gateway for people to sign up in 34 states. Sixteen states and the District of Columbia are running their own exchanges.
Need help with your insurance application? HealthCare.gov has tips for getting health insurance coverage.